To support or not?
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From: Illinois
To support or not?
Without everyone getting out of control can I get some legit info on a serious subject. There seems to be 2 different types of crank pulleys out there for our L's. 1 uses the factory support brace the other does not. Can anyone explain to me why you would want a non-supported crank pulley other than it's easier to change the accessory drive belt. That stock support brace I'm sure is there for a reason. Could it have something to do with the main bearings on the crank? I'm just looking for some important info so I don't make a critical mistake. Thanks Jeff
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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net
[This message has been edited by JeffsLightning (edited 05-27-2001).]
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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net
[This message has been edited by JeffsLightning (edited 05-27-2001).]
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From: lancaster,pa. usa
Now that ive changed the lower pulley with the PSP pulley i believe i know why the support cage is on the STOCK pulley yes its to save on the main bearing in my opinion. however the reason the cage and bearing are needed for the STOCK pulley is because this STOCK pulley weighs a TON! you can't possible put something that heavey out on the front of the crank without doing damage unless you support it with a cage and bearing! so ford did an awsome job designing the cage for the STOCK pulley... Now the pulley that PSP sells and myself is like a feather compared to the STOCK pulley..its superlight weight and in my opinion the cage and bearing are not needed to support such a heavey weight anymore..when you remove your stock pulley you'll see what i mean, this thing is HEAVY.. so without adoubt (Imho) the PSP pulley is definatly safe and is very light! and makes some serious boost! 
JL
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JL------------------
93 cobra 10.90@127.00
99 lightning (black)
E.T. 12.06
best mph 112
60 ft. 1.65
(All Throttle No Bottle!)
JL ram air
JL Powercooler
2# pulley
Level 10 shift kit
Test Converter!
DiabloSport Dist.!
(KEEP IT BETWEEN THE LINES!)
F-150 Supporting Vendor
_ _ _ _ _ _ _ _ _ _ _ _ _
JohnnyLightning Performance
E-mail: jlightningracing@cs.com
JohnnyLightningWebpage
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Joined: Aug 1999
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From: Palm Coast, FL
Jeff, this debate over the pulley situation was covered in detail on the SVT/JDM site. I will copy my post from over there below:
"Since I have dealt with the people invloved with the design of the stock set up, let me pass along some info on the subject. The stock cage set up was designed to support the heavy weight of the stock pulley. The entire stock set up with the rubber mounted pulley, was designed to reduce the noise created by the blower, since the normal "whine" was not acceptable for production purposes. Removing the rubber isolated stock pulley allows that noise to come back, so having the cage with a solid mounted pulley negates the original design reason for having it. Some people say that removing the cage puts extra stress on the crank. Theoretically, that makes sense. But on our set up, with our kind of blower, the extra "pull" on the crank is barely measuarbale. Let me explain. Crank stress issues are common concerns in the racing world, but only on vehicles that use solid tension adjusters. When a guy with a Vortech super tighetens his belt to eliminate slip, that stresses the crank snout. On our trucks, our blowers use a spring loaded belt tensioner. Any excessive "pull" from the blower is absorbed by the tensioner, NOT the crankshaft, that's why it's there. Think about it; superchargers have been used for over 50 years on production cars. Do any other models use crank supports? NO. Do the worlds greatest aftermarket car builders like Roush, Saleen, and Kenne Bell use them on thier dealer sold and fully warrentied new blown cars? NO. Did Ford use on on the SuperCoupe. NO. Do SuperCoupes have problems with the cranks failing from blower stress? NO. Millions and millions of blown vehciles exsist today, and the only ones that suffer from crank issues, are ones where the belts have been overtightened to reduce slip. There is also another issue on this subject that many have not caught on to. The caged pulley set up is driven off the adapter bolted to the crank. Now, lets take off the stock setup and press the stock pulley off to re-use the cage and install a new solid, cage mounted pulley. You take the new pulley, press the new bearing in, press the assembly back onto the cage an place it on the truck. You now screw the pulley back onto the adapter and bolt the cage back on. You now have a fully solid caged pulley. When you pressed that new pulley on, did you know EXACTLY where to stop? Everything is now soild mounted, so if you're off a thousands of an inch, guess what, your new pulley is now either PUSHING or PULLING on the crank! Say bye-bye to your thrust bearing after a little while Sometimes you have to look deeper than the obvious when you are deciding on new products. I don't sell stuff that I don't feel is safe. I've had the cageless pulley on my truck for almost a year now. I've got close to 120 passes on the truck with it. I've got no problems related to it. Now you can take this post anyway you like. if you're a JDM advocate, you'll probably say "screw Sal, he's just trying to beat out JDM". If you said that, then you didn't read this post for it's info, you read it for an excuse to flame me, and that's too bad. If you now look at the pulley subject in a new light, then good, this post was meant to educate, not flame. I don't lie, I don't BS, I just put forward the truth, use it as you like."
Keep in mind that this was a post taken from the SVT/JDM site and I may sound a bit crude in the delivery of my information, that is because the thread was getting a bit heated.
Hope this helps.
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SAL - TEAM PSP
web- www.powersurgeperformance.net
E-mail sales@powersurgeperformance.net
tech@powersurgeperformance.net
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"Since I have dealt with the people invloved with the design of the stock set up, let me pass along some info on the subject. The stock cage set up was designed to support the heavy weight of the stock pulley. The entire stock set up with the rubber mounted pulley, was designed to reduce the noise created by the blower, since the normal "whine" was not acceptable for production purposes. Removing the rubber isolated stock pulley allows that noise to come back, so having the cage with a solid mounted pulley negates the original design reason for having it. Some people say that removing the cage puts extra stress on the crank. Theoretically, that makes sense. But on our set up, with our kind of blower, the extra "pull" on the crank is barely measuarbale. Let me explain. Crank stress issues are common concerns in the racing world, but only on vehicles that use solid tension adjusters. When a guy with a Vortech super tighetens his belt to eliminate slip, that stresses the crank snout. On our trucks, our blowers use a spring loaded belt tensioner. Any excessive "pull" from the blower is absorbed by the tensioner, NOT the crankshaft, that's why it's there. Think about it; superchargers have been used for over 50 years on production cars. Do any other models use crank supports? NO. Do the worlds greatest aftermarket car builders like Roush, Saleen, and Kenne Bell use them on thier dealer sold and fully warrentied new blown cars? NO. Did Ford use on on the SuperCoupe. NO. Do SuperCoupes have problems with the cranks failing from blower stress? NO. Millions and millions of blown vehciles exsist today, and the only ones that suffer from crank issues, are ones where the belts have been overtightened to reduce slip. There is also another issue on this subject that many have not caught on to. The caged pulley set up is driven off the adapter bolted to the crank. Now, lets take off the stock setup and press the stock pulley off to re-use the cage and install a new solid, cage mounted pulley. You take the new pulley, press the new bearing in, press the assembly back onto the cage an place it on the truck. You now screw the pulley back onto the adapter and bolt the cage back on. You now have a fully solid caged pulley. When you pressed that new pulley on, did you know EXACTLY where to stop? Everything is now soild mounted, so if you're off a thousands of an inch, guess what, your new pulley is now either PUSHING or PULLING on the crank! Say bye-bye to your thrust bearing after a little while Sometimes you have to look deeper than the obvious when you are deciding on new products. I don't sell stuff that I don't feel is safe. I've had the cageless pulley on my truck for almost a year now. I've got close to 120 passes on the truck with it. I've got no problems related to it. Now you can take this post anyway you like. if you're a JDM advocate, you'll probably say "screw Sal, he's just trying to beat out JDM". If you said that, then you didn't read this post for it's info, you read it for an excuse to flame me, and that's too bad. If you now look at the pulley subject in a new light, then good, this post was meant to educate, not flame. I don't lie, I don't BS, I just put forward the truth, use it as you like."
Keep in mind that this was a post taken from the SVT/JDM site and I may sound a bit crude in the delivery of my information, that is because the thread was getting a bit heated.
Hope this helps.
------------------
SAL - TEAM PSP
web- www.powersurgeperformance.net
E-mail sales@powersurgeperformance.net
tech@powersurgeperformance.net
F-150 Online Supporting Vendor
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From: Auburn Wa
I'd like to add one more thing, peaple keep questioning the extra pressure on the front main bearing. The front main bearing on a V-8 is the least stressed bearing in the hole engine. It really only has 1 piston pounding on it, but the 2nd, 3rd etc. have 2 pistons pounding down on them. The front main has to support about half the pressure as the rest of the mains and furthermore the stress of the supercharger drive is trying to pull the crankshaft towards the upper half of the bearing, not push down on it.
And I've seen the inside of a lightning engine, the last thing you have to worry about is crank and bearing strength.
The cage is there, to take pressure off of the stock DAMPER, but when you remove all the weight, its not an issue anymore.
Dale
And I've seen the inside of a lightning engine, the last thing you have to worry about is crank and bearing strength.
The cage is there, to take pressure off of the stock DAMPER, but when you remove all the weight, its not an issue anymore.
Dale
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From: Illinois
Thanks for the straight forward answers guys. I think you can understand why I had concern. Jeff
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99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net
------------------
99.5 Lightning
Gone but not forgotten
01 picked up on 5/5/01
hud@mc.net
Senior Member
Joined: Jul 2001
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From: Nashville
I struggled with this question also. I have JL's lower pulley and an LFP upper pulley. I haven't heard anything bad happening to the crank or bearings. We have a belt tensioner also which takes some stress out also. I just saw this car at a local car show. He doesn't have a tensioner and this is a huge blower. He doesn't have a cage. I'm not a mechanic or anything, but it seems to me that if a cage was needed he would have one, especially after spending big money on a motor like that.
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From: Waltham Ma.
I struggled with the same thing too, while I waited for Jim tp come out with his pulley. I allmost went with one of the unsuported pulleys, but I am glad I waited for the JDM pulley. It is so smooth, and the extra power and the boost response is awsome.
I am sure the pulleys with out a cage would be OK but I am glad I have the cage, it gives me peice of mind knowing that the cage is still there.
I am sure the pulleys with out a cage would be OK but I am glad I have the cage, it gives me peice of mind knowing that the cage is still there.
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From: La Habra, CA
Guys, I have been around blown motors for years. I have a friend who at one time had 18 street rods. All but a couple had blowers on them. We did a lot of engine building, and modifying on blown engines (both superchaged and blown up).
Does the pull of the blower belt have an affect on the front main bearing. I would have to say most definitely, it does. Is it a problem? From my experience, rarely! Let me explain.
Like Sal said, if you are trying to get 13-15 lbs out of a centrifugal blower, you need one hellacious amount of belt tension, or a cog belt (which comes with its own set of problems). It is the belt tension that causes the upper front main bearing to wear.
If you go with toothed belt, which barely needs any tension to work properly, you won't see much wear in the front main. I have taken apart many Chevy blower motors that showed virtually no wear at all. This was due to the fact that almost all of these had toothed belts to drive the blower.
Our trucks do not have a toothed belt, but have a system which allows the belt to wrap around the smaller, top pulley with over 180 degrees of contact. Bacause of this, we do not need anything more that a simple tensioner to keep the belt from sliping. I don't think you will see any appreciable wear in the upper front main bearing on our motors.
A centrifugal, on the other hand, usually does not have much more that 90-120 degrees of wrap. They require a large amount of belt tension, and as older belt will slip anyway as it becomes wear hardened.
This higher amount of tension may cause wear over the life of the engine. I know a couple of guys that have 130,000 miles on their Vortech blown mustangs, and have never had bearing problems. They are, however, very good at changing head gaskets.
Does the pull of the blower belt have an affect on the front main bearing. I would have to say most definitely, it does. Is it a problem? From my experience, rarely! Let me explain.
Like Sal said, if you are trying to get 13-15 lbs out of a centrifugal blower, you need one hellacious amount of belt tension, or a cog belt (which comes with its own set of problems). It is the belt tension that causes the upper front main bearing to wear.
If you go with toothed belt, which barely needs any tension to work properly, you won't see much wear in the front main. I have taken apart many Chevy blower motors that showed virtually no wear at all. This was due to the fact that almost all of these had toothed belts to drive the blower.
Our trucks do not have a toothed belt, but have a system which allows the belt to wrap around the smaller, top pulley with over 180 degrees of contact. Bacause of this, we do not need anything more that a simple tensioner to keep the belt from sliping. I don't think you will see any appreciable wear in the upper front main bearing on our motors.
A centrifugal, on the other hand, usually does not have much more that 90-120 degrees of wrap. They require a large amount of belt tension, and as older belt will slip anyway as it becomes wear hardened.
This higher amount of tension may cause wear over the life of the engine. I know a couple of guys that have 130,000 miles on their Vortech blown mustangs, and have never had bearing problems. They are, however, very good at changing head gaskets.